clockchips.h (7445B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2/* linux/include/linux/clockchips.h 3 * 4 * This file contains the structure definitions for clockchips. 5 * 6 * If you are not a clockchip, or the time of day code, you should 7 * not be including this file! 8 */ 9#ifndef _LINUX_CLOCKCHIPS_H 10#define _LINUX_CLOCKCHIPS_H 11 12#ifdef CONFIG_GENERIC_CLOCKEVENTS 13 14# include <linux/clocksource.h> 15# include <linux/cpumask.h> 16# include <linux/ktime.h> 17# include <linux/notifier.h> 18 19struct clock_event_device; 20struct module; 21 22/* 23 * Possible states of a clock event device. 24 * 25 * DETACHED: Device is not used by clockevents core. Initial state or can be 26 * reached from SHUTDOWN. 27 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT. 28 * PERIODIC: Device is programmed to generate events periodically. Can be 29 * reached from DETACHED or SHUTDOWN. 30 * ONESHOT: Device is programmed to generate event only once. Can be reached 31 * from DETACHED or SHUTDOWN. 32 * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily 33 * stopped. 34 */ 35enum clock_event_state { 36 CLOCK_EVT_STATE_DETACHED, 37 CLOCK_EVT_STATE_SHUTDOWN, 38 CLOCK_EVT_STATE_PERIODIC, 39 CLOCK_EVT_STATE_ONESHOT, 40 CLOCK_EVT_STATE_ONESHOT_STOPPED, 41}; 42 43/* 44 * Clock event features 45 */ 46# define CLOCK_EVT_FEAT_PERIODIC 0x000001 47# define CLOCK_EVT_FEAT_ONESHOT 0x000002 48# define CLOCK_EVT_FEAT_KTIME 0x000004 49 50/* 51 * x86(64) specific (mis)features: 52 * 53 * - Clockevent source stops in C3 State and needs broadcast support. 54 * - Local APIC timer is used as a dummy device. 55 */ 56# define CLOCK_EVT_FEAT_C3STOP 0x000008 57# define CLOCK_EVT_FEAT_DUMMY 0x000010 58 59/* 60 * Core shall set the interrupt affinity dynamically in broadcast mode 61 */ 62# define CLOCK_EVT_FEAT_DYNIRQ 0x000020 63# define CLOCK_EVT_FEAT_PERCPU 0x000040 64 65/* 66 * Clockevent device is based on a hrtimer for broadcast 67 */ 68# define CLOCK_EVT_FEAT_HRTIMER 0x000080 69 70/** 71 * struct clock_event_device - clock event device descriptor 72 * @event_handler: Assigned by the framework to be called by the low 73 * level handler of the event source 74 * @set_next_event: set next event function using a clocksource delta 75 * @set_next_ktime: set next event function using a direct ktime value 76 * @next_event: local storage for the next event in oneshot mode 77 * @max_delta_ns: maximum delta value in ns 78 * @min_delta_ns: minimum delta value in ns 79 * @mult: nanosecond to cycles multiplier 80 * @shift: nanoseconds to cycles divisor (power of two) 81 * @state_use_accessors:current state of the device, assigned by the core code 82 * @features: features 83 * @retries: number of forced programming retries 84 * @set_state_periodic: switch state to periodic 85 * @set_state_oneshot: switch state to oneshot 86 * @set_state_oneshot_stopped: switch state to oneshot_stopped 87 * @set_state_shutdown: switch state to shutdown 88 * @tick_resume: resume clkevt device 89 * @broadcast: function to broadcast events 90 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration 91 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration 92 * @name: ptr to clock event name 93 * @rating: variable to rate clock event devices 94 * @irq: IRQ number (only for non CPU local devices) 95 * @bound_on: Bound on CPU 96 * @cpumask: cpumask to indicate for which CPUs this device works 97 * @list: list head for the management code 98 * @owner: module reference 99 */ 100struct clock_event_device { 101 void (*event_handler)(struct clock_event_device *); 102 int (*set_next_event)(unsigned long evt, struct clock_event_device *); 103 int (*set_next_ktime)(ktime_t expires, struct clock_event_device *); 104 ktime_t next_event; 105 u64 max_delta_ns; 106 u64 min_delta_ns; 107 u32 mult; 108 u32 shift; 109 enum clock_event_state state_use_accessors; 110 unsigned int features; 111 unsigned long retries; 112 113 int (*set_state_periodic)(struct clock_event_device *); 114 int (*set_state_oneshot)(struct clock_event_device *); 115 int (*set_state_oneshot_stopped)(struct clock_event_device *); 116 int (*set_state_shutdown)(struct clock_event_device *); 117 int (*tick_resume)(struct clock_event_device *); 118 119 void (*broadcast)(const struct cpumask *mask); 120 void (*suspend)(struct clock_event_device *); 121 void (*resume)(struct clock_event_device *); 122 unsigned long min_delta_ticks; 123 unsigned long max_delta_ticks; 124 125 const char *name; 126 int rating; 127 int irq; 128 int bound_on; 129 const struct cpumask *cpumask; 130 struct list_head list; 131 struct module *owner; 132} ____cacheline_aligned; 133 134/* Helpers to verify state of a clockevent device */ 135static inline bool clockevent_state_detached(struct clock_event_device *dev) 136{ 137 return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED; 138} 139 140static inline bool clockevent_state_shutdown(struct clock_event_device *dev) 141{ 142 return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN; 143} 144 145static inline bool clockevent_state_periodic(struct clock_event_device *dev) 146{ 147 return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC; 148} 149 150static inline bool clockevent_state_oneshot(struct clock_event_device *dev) 151{ 152 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT; 153} 154 155static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev) 156{ 157 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED; 158} 159 160/* 161 * Calculate a multiplication factor for scaled math, which is used to convert 162 * nanoseconds based values to clock ticks: 163 * 164 * clock_ticks = (nanoseconds * factor) >> shift. 165 * 166 * div_sc is the rearranged equation to calculate a factor from a given clock 167 * ticks / nanoseconds ratio: 168 * 169 * factor = (clock_ticks << shift) / nanoseconds 170 */ 171static inline unsigned long 172div_sc(unsigned long ticks, unsigned long nsec, int shift) 173{ 174 u64 tmp = ((u64)ticks) << shift; 175 176 do_div(tmp, nsec); 177 178 return (unsigned long) tmp; 179} 180 181/* Clock event layer functions */ 182extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt); 183extern void clockevents_register_device(struct clock_event_device *dev); 184extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu); 185 186extern void clockevents_config_and_register(struct clock_event_device *dev, 187 u32 freq, unsigned long min_delta, 188 unsigned long max_delta); 189 190extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); 191 192static inline void 193clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 maxsec) 194{ 195 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, maxsec); 196} 197 198extern void clockevents_suspend(void); 199extern void clockevents_resume(void); 200 201# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 202# ifdef CONFIG_ARCH_HAS_TICK_BROADCAST 203extern void tick_broadcast(const struct cpumask *mask); 204# else 205# define tick_broadcast NULL 206# endif 207extern int tick_receive_broadcast(void); 208# endif 209 210# if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) 211extern void tick_setup_hrtimer_broadcast(void); 212extern int tick_check_broadcast_expired(void); 213# else 214static inline int tick_check_broadcast_expired(void) { return 0; } 215static inline void tick_setup_hrtimer_broadcast(void) { } 216# endif 217 218#else /* !CONFIG_GENERIC_CLOCKEVENTS: */ 219 220static inline void clockevents_suspend(void) { } 221static inline void clockevents_resume(void) { } 222static inline int tick_check_broadcast_expired(void) { return 0; } 223static inline void tick_setup_hrtimer_broadcast(void) { } 224 225#endif /* !CONFIG_GENERIC_CLOCKEVENTS */ 226 227#endif /* _LINUX_CLOCKCHIPS_H */